<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        #box1 {
            color: pink;
        }

        #box2 {
            color: blueviolet;
        }

        #box3 {
            color: blanchedalmond;
        }
    </style>
</head>

<body>
    <div>
        <!-- 一个id只能用在一个标签上 -->
        <h4 id="box1">sddfsvdv</h4>
        <h4 id="box2">sddfsvdv</h4>
        <h4 id="box3">sddfsvdv</h4>
        <h4>sddfsvdv</h4>
    </div>
</body>

</html>